Absorbent articles of the above mentioned kind comprise an absorbent core and a cover enclosing the absorbent core. The cover comprises a liquid pervious cover on the body facing side of the absorbent core, often referred to as a topsheet or liner, and a liquid impervious cover on the garment facing side of the absorbent core, often referred to as a backsheet. Bodily fluids, especially urine, easily penetrate the liquid pervious cover and are absorbed and retained by the absorbent core. Bodily exudates in solid or semi-solid state however, such as fecal materials, can not penetrate the liquid pervious cover and are normally inhibited from leaking out of the article by elasticized waistbands and leg cuffs. Additional barrier flaps are often provided between the leg openings and the absorbent core to further inhibit leakage.
It is further known to deal with fecal materials by providing a topsheet that conforms closely to the wearer and which has a large aperture that is intended to register with the anal opening, so that fecal material passes through the aperture into a void space, where it is kept isolated from the wearer. An example of such a diaper is shown in U.S. Pat. No. 5,957,907.
However these attempts do not solve the problem of handling low-viscosity fecal material that is prevalent in younger children, especially those who are breast fed. Low-viscosity fecal material easily moves around on the body facing side of the topsheet under the influence of gravity, motion and pressure by the wearer. The migration of the fecal material often moves it to the perimeter of the article, increasing the likelihood of leakage, and further smears it against the skin of the wearer making cleanup more difficult.
One attempt of dealing with low-viscosity fecal matter is described in U.S. Pat. No. 5,342,338, which discloses a topsheet having apertures large enough for low-viscosity fecal material to pass through to a secondary topsheet. The secondary topsheet immobilizes the fecal material in position for dewatering.
Another attempt is described in WO 00/28929 disclosing an apertured liner arranged as body facing cover in the rear portion of the article. In a preferred embodiment the apertured liner is a hydrophobic film laminated to fibrous layer, which provides a mechanism for absorbing and containing fecal materials which have passed through the apertured film layer.
WO 99/55273 describes an apertured laminate which is told to be adapted to handle low-viscosity fecal material. The laminate comprises first and second liquid pervious materials each having apertures with a defined effective size. The apertures of the first and second materials are aligned and the second material preferably has a hydrophilicity that is greater than the hydrophilicity of the first material.
EP-A-1 236 827 discloses an absorbent web suitable as body-side liner for absorbent articles. The web comprises a hydrophilic base sheet having a three-dimensional topography and wherein hydrophobic matter has been applied to the elevated regions. The web is told to give an improved clean, dry feel against the skin of the wearer. The problem of handling low-viscosity fecal material is not discussed in this document.